Metamath Proof Explorer
Description: Distinct variable version of ax-6 , distinct variables case.
(Contributed by Mario Carneiro, 14-Aug-2015)
|
|
Ref |
Expression |
|
Assertion |
ax-9d2 |
|- -. A. x -. x = y |
Detailed syntax breakdown
| Step |
Hyp |
Ref |
Expression |
| 0 |
|
vx |
|- x |
| 1 |
0
|
cv |
|- x |
| 2 |
|
vy |
|- y |
| 3 |
2
|
cv |
|- y |
| 4 |
1 3
|
wceq |
|- x = y |
| 5 |
4
|
wn |
|- -. x = y |
| 6 |
5 0
|
wal |
|- A. x -. x = y |
| 7 |
6
|
wn |
|- -. A. x -. x = y |